56644387681 has 8 divisors (see below), whose sum is σ = 64739663424. Its totient is φ = 48549917040.

The previous prime is 56644387487. The next prime is 56644387691. The reversal of 56644387681 is 18678344665.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 56644387681 - 2²⁵ = 56610833249 is a prime.

It is a super-2 number, since 2×56644387681² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56644387691) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42115 + ... + 339208.

It is an arithmetic number, because the mean of its divisors is an integer number (8092457928).

Almost surely, 2^56644387681 is an apocalyptic number.

It is an amenable number.

56644387681 is a deficient number, since it is larger than the sum of its proper divisors (8095275743).

56644387681 is a wasteful number, since it uses less digits than its factorization.

56644387681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402551.

The product of its digits is 23224320, while the sum is 58.

The spelling of 56644387681 in words is "fifty-six billion, six hundred forty-four million, three hundred eighty-seven thousand, six hundred eighty-one".